Impact crimping tool



y 2, 1967 P. J. SPANGLER 3,316,744

IMPACT CRIMP ING TOOL Filed July 8, 1964 Fig. 5

INVENTOR. PAUL J. SPANGLER ATTOR N EYS BY a wM United States Patent Ghio Filed July 8, 1964, Ser. No. 381,126 1 Claim. (Cl. 72-35) This invention relates to the crimping of electrical connectors onto conductors and, more particularly, to tools for crimping the tubular ferrule portion of electrical connectors onto conductors.

The invention involves a relatively simple and inexpensive bench-type impact tool which may be operated by a hammer or by a bench vise to produce secure joints between the metal parts to be joined. The invention is particularly concerned with effecting mechanically strong, electrically conductive connections of electrical terminals and connectors to stranded and solid wire conductors for the purpose of either terminating the conductors or connecting them to other conductors by a relatively simple and straightforward method requiring no expensive tools.

The crimping tool according to this invention employs a fixed female die nest and a movable male die member. These elements are designed to accommodate a wide range of terminals and connectors, including A.W.G. numbers 8, 6, 4, 2, l/O, 2/0, 3/0, and 4/0. Since the tool according to this invention is inexpensive and is capable of crimping a wide variety of terminal and connector sizes without changing the die surfaces, it is particularly suitable for home or shop use and other applications where terminals and connectors are to be crimped onto conductors on a non-production basis.

The die surfaces that are employed in the tool according to this invention are preferably of the type that produce an indentation-type crimp by a single or double indentor male die which cooperates with a V-shaped female die nest to produce a V or a W crimp. The V- shaped female die nest accommodates the wide variety of terminals and connectors as distinguished from a relatively narrow range of terminals or connectors that may be accommodated by a single die of the confined crimp type. It is to be understood, however, that the invention is not restricted to any particular die configuration.

A particularly advantageous feature of the tool according to this invention is that a desired crimping configuration between the male and female die members is achieved without the conventional provision of mechanical stop means between the male and female die elements. Heretofore, mechanical stops were provided between the male and female dies to insure that a connector or terminal would not be over or'undercrimped, and so that a desired crimped cross section would be achieved. Tools having mechanical stop elements, therefore, are not capable of crimping a wide variety of terminals and connectors in that a single crimped cross section is produced by a single pair of dies and, since this cross section is not suitable for all terminals and connectors, such tools must be provided with interchangeable dies. Although interchangeable dies are suitable for production crimping operations, the cost of such dies makes the tool unsuitable for non-production crimping operations.

It is an object of the present invention to provide a small, lightweight, portable crimping tool that is suitable for crimping a wide variety of terminals and connectors and which produces a crimped connection between a conductor and a connector that is mechanically and electrically equivalent to a connection produced by large production tools.

It is a further object of this invention to provide a crimping tool which may be operated by a hammer or by insertion in a vise, and which has a single set of dies that define a wide variety of crimping configurations without the provision of mechanical stop elements.

Other objects, features, and advantages of the invention will become apparent from the following detailed description and from the accompanying drawings.

In the drawings:

FIGURE 1 is a side elevational view of a crimping tool according to this invention.

FIGURE 2 is a rear elevational view of the crimping tool seen in FIGURE 1.

FIGURE 3 is a cross sectional view of the tool according to this invention, showing the ferrule portion of a connector inserted in the tool, the plane of the section being indicated by the line 3-3 in FIGURE 2.

FIGURE 4 is a fragmentary, cross sectional view of the tool according to this invention, the plane of the section being indicated by the line 44 in FIGURE 3.

FIGURE 5 is a cross sectional view of the tool according to this invention, the plane of the section being indicated by the line 55 in FIGURE 3.

Referring now to the drawings, an impact crimping tool 10 is illustrated. The tool 10 includes a base 11 and a ram 12. The ram 12 has a cylindrical body portion 13 which is slidably mounted in a vertical bore 14, which is provided in the base 11. An opening 15 is provided in the base 11 to expose the lower end of the ram 12 and a lower female die member 16. This lower die member 16 is provided with a cylindrical bottom portion 17 and upwardly extending sidewalls 18, which are tangent to the bottom portion 17.

The ram 12 has a tapered lower end 19 which includes a pair of conical side surfaces 29 and a pair of flat front and back surfaces 21. The slope of the front and back surfaces 21 corresponds to the slope of the sidewalls 18 in the die member 16. A cross 22 is cut into the tip of the ram 12 and defines projecting ferrule indenting surfaces 23. A pin 24 is threaded into the body portion 13 of the ram 12 and extends through a vertical slot 25 from the back of the base 11 to the bore 14. A bore 26 is drilled vertically through the base 11 and communicates with the slot 25. A coil spring 27 is looped over the pin 24 and extends through the bore 26. The bottom end of the coil spring 27 is hooked into a depression 28 in the base 11.

As may be seen in FIGURE 1, the ram 12 is biased by the spring 27 so that its tip rests against the conical surface 17 of the die portion 16. In order to crimp the ferrule portion of a connector or terminal onto a conductor, the pin 24 is raised and the ferrule portion is placed on the die portion 16. The pin 24 is then released so that the tip of the ram 12 rests against the ferrule to hold the ferrule in place. The bared end of a conductor is then inserted into the open end of the ferrule and this assembly is crimped together by striking the top of the ram 12 with a hammer. If desired, however, this as sembly may be crimped together by placing the device 10 in a vise so that the jaws of the vise will move the ram toward the die portion 15.

As may be seen in FIGURES 1 and 2, suitable indicia are provided on the back and sides of the base 11 to indicate when the ferrule is properly crimped. The pin 24 and the indicia are located on the ram 12 and the base 11, respectively, so that the upper surface of the pin 24 is aligned with a particular indicia when the ram 12 and the die portion 16 define a crimping configuration that corresponds to the particular indicia selected. Thus it may be seen that a range of terminals and connectors may be crimped by the tool 10 without changing dies, as would be required if mechanical stop means were provided between the ram 12 and the die portion 16.

Obviously, many modifications and variations of the invention will become apparent to those skilled in the art in the light of the above teachings. Therefore, it is to be understood that, within the spirit and scope of the appended claim, the invention may be practiced otherwise than as specifically shown and described.

What is claimed is:

An impact crimping tool comprising a base, a smooth walled vertical bore in said base, a smooth walled ram slidably mounted for axial movement in said bore and having a bottom end defining a first ferrule crimping surface, the bottom of said bore defining a second ferrule crimping surface which is opposed to said first ferrule crimping surface, an opening in said base communicating with said bore and said second surface so that a tubular ferrule may be placed on said second surface, a pin fixed to said ram and extending through a vertical slot in said base, a spring fixed to said pin and to said base and biasing said ram toward said second surface so that a ferrule may be retained between the second surface and the spring biased ram, indicia means on said base and adjacent said slot, said first and second ferrule crimping surfaces defining one of a series of desired cross sectional crimping configurations when said pin is aligned with a selected indicia means.

References Cited by the Examiner UNITED STATES PATENTS 2,426,492 8/1947 Dupre 724l2 2,744,429 5/1956 Seely 724l2 2,878,854 3/1959 Batcheller 724l2 2,910,108 10/1959 Pike 7255 CHARLES W. LANHAM, Primary Examiner.

R. D. GREFE, Assistant Examiner. 

